Ramp control for a front fork of a bicycle

ABSTRACT

A suspension unit for a front fork of a vehicle includes an annular tube. The first tube defines a compression chamber and a damping chamber. A damper includes a first valve allowing gas to variably flow from the compression chamber to the damping chamber and a second valve allowing gas to flow from the damping chamber to the compression chamber. An external adjuster allows a rider to adjust the first valve to improve ride conditions.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application claims priority to U.S. Provisional PatentApplication Ser. No. 61/974,469 and U.S. patent application Ser. No.14/676,071, now U.S. Pat. No. 9,573,649, the disclosures of which areincorporated herein by reference.

STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH AND DEVELOPMENT

(Not Applicable)

REFERENCE TO AN APPENDIX

(Not Applicable)

BACKGROUND OF THE INVENTION

The present disclosure relates generally to suspension components onvehicles. More particularly, the present disclosure relates to a shockabsorber with an external, on-the-fly adjuster to vary damping of asuspension for use on a bicycle.

For many cyclists, it is important to be able to vary the rate at whichthe front fork of the bicycle compresses when it hits an obstacle. Somecyclists prefer a stiffer feel, while others prefer a softer feel. Stillothers have differing preferences depending on the particular terrainand objects likely to be encountered in an off-road context.

Shock absorbers that support the weight of the vehicle with compressedgas or another compressible gas instead of coil or leaf springs may beattractive for applications where the weight of components must be keptas low as possible. Moreover, gas spring shocks may allow for convenientadjustability of the spring rate of the suspension, in some cases byincreasing or decreasing the volume of gas within the shock.

In many conventional devices, an air spring is commonly used inconjunction with a damping device to control compression and rebound, atleast in part. The damping device conventionally controls damping bycontrolling the flow of a substantially incompressible fluid. Makingchanges to the damping characteristics of the damping device,particularly during a ride, may be complicated. Further, suchadjustments are often only useful to change the damping characteristicsover a certain range of travel of the fork, while leaving the dampingcharacteristics at other ranges of travel unaffected.

The need therefore exists for a shock absorber that allows a rider toadjust the damping rate by controlling the flow of a compressible gaswithin a fork. Using such a system, a rider can adjust the ride feel onthe fly.

BRIEF SUMMARY OF THE INVENTION

In one embodiment, a suspension unit for a bicycle may include anannular tube, a piston, a barrier assembly, and a first valve. Theannular tube may define a compression chamber. The piston may slidinglyinterfit with the annular tube and be capable of compressing acompressible gas in the compression chamber. The barrier assembly may beremote from the piston. The barrier assembly may include a dampingbarrier near one end of the annular tube. The compression chamber may beon one side of the barrier assembly and a damping chamber may be onanother side of the barrier assembly. The first valve may be operativelybetween the compression chamber and the damping chamber. The first valvemay be capable of permitting the compressed gas to flow between thecompression chamber and the damping chamber. An effective force may beapplied to a blocker in the first valve, the effective force influencinga threshold level of force of compressed gas in the compression chambercapable of opening the first valve.

The effective force may be at least partially applied by a bias. Thebias may be a spring. The blocker may comprise a resilient material. Theresilient material may apply at least part of the effective force. Thebarrier assembly may be connected to the tube in a substantially fixedposition. The barrier assembly may be adjustably connected to theannular tube. The barrier assembly may be located substantially withinthe annular tube. The suspension unit may further include an adjuster.The adjuster may be operatively connected to the first valve and may becapable of adjusting at least a portion of the effective force. Thebarrier assembly and a shaft connecting the barrier assembly to theannular tube may at least partially define a serpentine passageway. Asecond valve may be operatively between the compression chamber and thedamping chamber and may be capable of permitting the compressible gas toflow between the damping chamber and the compression chamber.

In another embodiment, a suspension unit for a bicycle includes anannular tube, a movable piston, a damping barrier, and a first valve.The annular tube may define a compression chamber and a damping chamber,each of the compression chamber and the damping chamber being filledwith a compressible gas. The movable piston may slidingly fit within theannular tube. The damping barrier may be connected to the annular tubeand remote from the movable piston. The compression chamber may be onone side of the damping barrier and a damping chamber may be on anotherside of the damping barrier. The first valve may be operatively betweenthe compression chamber and the damping chamber. The first valve maypermit the compressible gas to flow between the compression chamber andthe damping chamber. The first valve may include a first bias at leastpartially contributing to an effective force applied to a blocker. Theeffective force may be capable of being overcome by a threshold level offorce of compressed gas in the compression chamber.

The suspension unit may further include a second valve operativelybetween the compression chamber and the damping chamber. The secondvalve may permit the compressible gas to flow between the dampingchamber and the compression chamber. The second valve may include asecond bias capable of being overcome by a threshold level of force ofcompressed gas in the damping chamber. The second valve may include ashim. The second bias may include a second spring urging the shim into aclosed position.

The damping barrier may be connected to the first annular tube in asubstantially fixed position. The damping barrier may be locatedsubstantially within the annular tube. The damping barrier may beconnected to the first annular tube using a shaft that is annular alongat least a portion of its length. The damping barrier and the shaft mayat least partially define a serpentine pathway.

The first valve may be placed adjacent at least one of the barrier andthe shaft. The first valve may further include a first blocker. Thefirst bias may further include a first spring positioned adjacent thefirst blocker. The first bias may include a first blocker formed atleast in part from a resilient material. The first blocker may include apin. The first blocker may include a ball. The suspension unit mayfurther include an adjuster operatively connected to the first blockerand capable of adjusting an effective spring force of the resilientmaterial.

In another embodiment, a suspension unit for a bicycle includes anannular tube, a piston, a barrier assembly, a first valve, and anadjuster. The annular tube may define a compression chamber. The pistonmay slidingly interfit with the annular tube and may be capable ofreciprocating with respect to the annular tube. The piston may becapable of compressing a compressible gas in the compression chamber.The barrier assembly may be remote from the piston and near one end ofthe annular tube. The compression chamber may be on one side of thebarrier assembly and a damping chamber may be on another side of thebarrier assembly. The first valve may be operatively between thecompression chamber and the damping chamber. The first valve may becapable of permitting the compressible gas to flow between thecompression chamber and the damping chamber. The adjuster may beoperatively connected to the first valve and may have at least threepositions.

The suspension unit may further include a second valve operativelybetween the compression chamber and the damping chamber. The secondvalve may be capable of permitting the compressible gas to flow betweenthe damping chamber and the compression chamber. The first valve mayinclude a bias. The adjuster may be capable of adjusting an effectivespring force of the bias. The bias may be a spring. The adjuster may becapable of adjusting an effective spring force of the spring. The biasmay be a resilient material from which at least a portion of the firstvalve is formed. The adjuster may be capable of adjusting an effectivespring force of the resilient material. The adjuster may besubstantially infinitely adjustable between a first extreme position anda second extreme position.

The first valve may include a blocker adjustable by the adjuster betweena first position relatively substantially allowing the flow ofcompressed gas from the compression chamber to the damping chamber, asecond position relatively substantially restricting the flow ofcompressed gas from the compression chamber to the damping chamber, anda third position between the first position and the second positionrelatively partially restricting the flow of compressed gas from thecompression chamber to the damping chamber. The first bias may beadjustable by the adjuster between a first position relativelysubstantially allowing the flow of compressed gas from the compressionchamber to the damping chamber, a second position relativelysubstantially restricting the flow of compressed gas from thecompression chamber to the damping chamber, and a third position betweenthe first position and the second position relatively partiallyrestricting the flow of compressed gas from the compression chamber tothe damping chamber. A portion of the first valve may be adjustable bythe adjuster between a first position relatively substantially allowingthe flow of compressed gas from the compression chamber to the dampingchamber, a second position relatively substantially restricting the flowof compressed gas from the compression chamber to the damping chamber,and a third position between the first position and the second positionrelatively partially restricting the flow of compressed gas from thecompression chamber to the damping chamber.

In another embodiment, the suspension unit for a bicycle includes anannular tube, a piston, a barrier assembly, a first valve, and a firstpassageway. The annular tube may define a compression chamber. Thepiston may slidingly interfit with the first annular tube and may becapable of reciprocating with respect to the annular tube. The pistonmay be capable of compressing a compressible gas in the compressionchamber. The barrier assembly may be remote from the piston. The barrierassembly may include a damping barrier near one end of the annular tube.The compression chamber may be on one side of the barrier assembly and adamping chamber may be on another side of the barrier assembly. Thefirst valve may be operatively between the compression chamber and thedamping chamber. The first valve may be capable of permittingcompressible gas to flow between the compression chamber and the dampingchamber. The first passageway may be defined between the damping chamberand the compression chamber. Pressure from the compressible gas in thecompression chamber may be capable of variably opening the first valve,thereby changing an effective size of the first passageway.

The suspension unit may further include a second valve operativelybetween the compression chamber and the damping chamber. The secondvalve may be capable of permitting the compressible gas to flow betweenthe damping chamber and the compression chamber.

The first valve may further include a first bias. The first valve mayfurther include a first blocker. An effective spring force applied bythe first bias to the first blocker may at least partially define athreshold level of force in the compression chamber capable of openingthe first valve. The first bias may be a spring. The first valve mayinclude a first blocker comprising a resilient material, wherein aneffective spring force applied by the first blocker at least partiallydefines a threshold level of force in the compression chamber capable ofopening the first valve. An adjuster may be operatively connected to thefirst valve and may be capable of adjusting the variability of openingof the first passageway. The first passageway may be serpentine. Thebarrier assembly may be located substantially within the annular tube.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is an exterior side view of a front fork of a bicycle accordingto the disclosed embodiments;

FIG. 2 is a partial cross-sectional view of FIG. 1 showing a firstembodiment of the damping structure;

FIG. 3 is a detailed view of one embodiment of the area marked 3-3 inFIG. 2 with an adjuster in an intermediate position;

FIG. 4 is a detailed view of the embodiment of FIG. 3 with the adjusterin a first extreme position;

FIG. 5 is a detailed view of the embodiment of FIG. 3 with the adjusterin a second extreme position;

FIG. 6 is a top view of a representative adjuster according to theembodiment of FIG. 3;

FIG. 7 is a detailed view of an alternative adjustment embodiment toFIG. 3;

FIG. 8 is a detailed view of an alternative embodiment of the areamarked 3-3 in FIG. 2;

FIG. 9 is a detailed view of another alternative embodiment of the areamarked 3-3 in FIG. 2;

FIG. 10 is a detailed view of yet another alternative embodiment of thearea marked 3-3 in FIG. 2;

FIG. 11 is a detailed view of yet another alternative embodiment of thearea marked 3-3 in FIG. 2;

FIG. 12 is a detailed view of yet another alternative embodiment of thearea marked 3-3 in FIG. 2;

FIG. 13 is a detailed view of yet another alternative embodiment of thearea marked 3-3 in FIG. 2;

FIG. 14 is a detailed view of yet another alternative embodiment of thearea marked 3-3 in FIG. 2;

FIG. 15 is a side cross-sectional view of a rear shock absorber of abicycle according to the disclosed embodiments;

FIG. 16 is a side cross-sectional view of an alternative embodiment of arear shock absorber of a bicycle; and

FIG. 17 is a top cross-sectional view of the embodiment of FIG. 16.

In describing the preferred embodiment of the invention which isillustrated in the drawings, specific terminology will be resorted tofor the sake of clarity. However, it is not intended that the inventionbe limited to the specific term so selected and it is to be understoodthat each specific term includes all technical equivalents which operatein a similar manner to accomplish a similar purpose. For example, theword connected or terms similar thereto are often used. They are notlimited to direct connection, but include connection through otherelements where such connection is recognized as being equivalent bythose skilled in the art.

DETAILED DESCRIPTION OF THE INVENTION

The present application claims priority to U.S. Provisional PatentApplication Ser. No. 61/974,469, the disclosure of which is incorporatedherein by reference.

In this detailed description, various terms relating to direction may beused. The elements discussed herein relate to a bicycle. Because, in itsoperable position, a bicycle is oriented generally vertically, i.e.,perpendicular to the ground, the direction terms refer to the positionof an element relative to gravity when the bicycle is in its operableposition. Accordingly, for example, the term “downwardly” refers to thedirection towards the ground when the bicycle is in its operableposition, and the term “forwardly” relates to a direction towards afront wheel of the bicycle when it is in its operable position. Further,the terms “inboard” and “outboard” may be used. The term “inboard”describes a position between one item and a vertical plane substantiallybisecting the bicycle. The term “outboard” describes a position of anobject further from the vertical centerplane of the bicycle. Inaddition, the terms “bicycle” and “bike” are used hereininterchangeably. A person having ordinary skill in the art willunderstand that if something is referred to as one, it can refer to theother.

In the present disclosure, the suspension structure may be described asit relates to a bicycle. However, the suspension structure described inthe present embodiments may instead be applied to other vehicles. Thepresent suspension structure may be used with vehicles having adifferent number of wheels, for example. The suspension structure may beused in connection with a motorized vehicle.

The present disclosure describes a suspension system that is filled witha compressible gas. The compressible gas may be injected into thesuspension system in a known manner using conventional structure andtechnology. In the descriptions herein, it will be understood by aperson having ordinary skill in the art that the pressure within thesuspension unit at the beginning of a suspension stroke may besubstantially in equilibrium throughout the suspension system. A usermay select from a variety of pressures within the suspension unit,depending on the user's preferences regarding ride and handling and thedemands of a particular course the rider desires to ride. These factorsare all well-known in the art and are not described in detail herein.

In each of the embodiments described herein, there is described a firstvalve operatively positioned between and opening a first passagewaybetween a compression chamber and a damping chamber. The first valve maybe designed to open upon an increase in pressure in the compressionchamber, such that there is a pressure difference between the pressurein the compression chamber and pressure in the damping chamber. For eachembodiment, a threshold level of force of compressed gas in thecompression chamber is capable of opening the first valve. Thisthreshold level of force may primarily be governed by the design of thefirst valve. When the threshold level of force is present in thecompression chamber, the valve may open to at least some degree. Whenthe first valve includes a bias, the degree of opening of the valve andthe effective size of the first passageway may be governed at least inpart by the relative force on a blocker applied by the compressed gas inthe compression chamber and the force of the bias on the blocker.

It is to be appreciated by a person having ordinary skill in the artthat many of the described embodiments include a first valve designed togovern variable gas flow from the compression chamber to the dampingchamber and a second valve designed to govern variable gas flow from thedamping chamber to the compression chamber. However, in a real worldapplication of the device, some counter gas flow may be expected. Suchcounter flow will not be described in detail in each embodiment. Inaddition, in areas of the specification where directional gas flow maybe described, such flow should not be considered to be exclusive andwithout the possibility of counter flow. Instead, a person havingordinary skill in the art will understand that flow in other directionsis possible and expected. In many of the embodiments, the first andsecond valves may be designed to be check valves, which optimally allowfluid flow in only one direction and close immediately upon pressureequalization.

The structures described herein may be applied to either a front or rearsuspension of a vehicle, most particularly a bicycle. The remainingstructures present in the suspension may be illustrated and may bedescribed in at least a cursory fashion. However, these structures arenot critical to the use of the embodiments described herein. The presentembodiments could be incorporated with other suspensions that use acompressible gas. Accordingly, the suspension system elements shownshould not be construed as being limiting to the embodiments described.

Some embodiments are shown as being applied in the context of a frontsuspension and others in a rear suspension. In general, persons ofordinary skill in the art are familiar with the structural andfunctional differences and limitations between shock absorbers and canmake the necessary modifications to use the structures described hereinin context. However, a person of ordinary skill in the art is able tounderstand that any of the disclosed embodiments could, in theory, beused in another suspension system in current operation or laterdeveloped.

FIG. 1 illustrates a suspension system 100 for a vehicle (not shown).The embodiments shown are illustrated in the context of a bicycle.However, the designs could be modified for use with a vehicle havingmore than two wheels or a vehicle powered by a motor. The top end 102 ofthe suspension system may be attached to handle bars or another steeringsystem (not shown), manipulable by a rider to set and change thedirection of the vehicle. The bottom end 104 of the suspension system100 may include a first bracket 106 and a second bracket 108 that areconfigured to allow an axle 110 to be passed therethrough. The firstbracket 106 and the second bracket 108 may be any conventional open boreor closed bore bracket as desired by the designer. The axle 110 shownincludes a quick release 112. The use of such a quick release 112 isoptional and any mechanism for fixing the axle in place may besubstituted therefore. In operation, a hub and wheel (not shown) may bemounted in surrounding fashion to the axle 110.

Turning now to FIG. 2, the position of the damping structure for thesuspension system is shown. The suspension system 200 of the presentembodiments is shown as being in a single side of the fork 202. Inanother embodiment, it may be desirable to incorporate the dampedsuspension system in the other side of the fork 202 or to incorporate itin both sides of the fork 202. In still other embodiments, a fork withonly a single arm may be used, and the suspension system 200 may beincorporated therein. A designer is able to make such adjustmentswithout undue experimentation.

The fork shown in FIG. 2 has a first leg 272 and a second leg 274. Eachleg 272, 274 may incorporate a conventional structure and method forabsorbing force imparted to the frame (not shown) from impact betweenthe wheel (not shown) and other objects, including the weight of therider. Such structures are well-known by persons of ordinary skill inthe art. These structures are merely exemplary. Other structurescurrently known or developed in the future could be substituted thereforby a person of ordinary skill in the art without undue experimentation.

The suspension system 200 may include a first annular tube 204 and asecond annular tube 206. The first annular tube 204 may have a closedend 208 at the top of the fork and an opposing open end (not shown). Thesecond annular tube 206 may have a closed end 212 at the bottom of thefork and an opposing open end 214. In the embodiment shown, the open endof the first annular tube 204 may be configured to telescopically slideor interfit into the open end 214 of the second annular tube 206. Inother embodiments, it may be desirable for the open end 214 of thesecond annular tube 206 to fit within the open end of the first annulartube 204. Such design choices are within the knowledge and skill of adesigner in the art. Regardless of the precise configuration, the firstannular tube 204 and second annular tube 206 may be configured toslidingly and telescopically interfit with one another. The spacedefined within the first annular tube 204 and the second annular tube206 may be at least partially filled with one or more compressed gases,as will be described in greater detail below. In many configurations,the first annular tube 204 and the second annular tube 206 aresubstantially round in cross-sectional configuration.

A movable piston assembly 216 may be attached to the second annular tube206. In the embodiment shown, the movable piston assembly 216 may beattached to one end 217 of an annular shaft 218. A second, opposing end(not shown) of the annular shaft 218 may be attached to the secondannular tube 206. In the configuration shown in FIG. 2, the second endmay be attached adjacent the closed end 212 of the second annular tube206. Such a configuration is not required, but in many embodiments itmay be an efficient design. The length of the annular shaft 218 may bedetermined based on the length, circumference, and volume of the firstannular tube 204 and the second annular tube 206 based on conventionalcalculations.

The movable piston assembly 216 may include a movable piston 224 and anoptional seal 226. The movable piston assembly 216 may be designed toprevent or minimize the passage of compressed gas between thecompression chamber 228 and a lower chamber 230. In many embodiments,because the movable piston 224 is configured to move, it may bedesirable for the movable piston 224 to have a smaller diameter than thediameter of the first annular tube 204. The seal 226 may be configuredto bridge the distance between the diameter of the movable piston 224and the diameter of the first annular tube 204. Such a seal 226 isconventional and may be selected by a person having ordinary skill inthe art in a known manner based, at least in part, on manufacturingtolerances, size, and the desired pressure of the pressurized gas withinthe first annular tube 204 and the second annular tube 206. The pistonassembly 216, shaft 218, and much of the remainder of the suspensionsystem are merely shown and described generally and schematically. Othersuspension structures could be easily substituted therefor.

A damper 250 may be incorporated near the closed end 208 of the firstannular tube 204. One exemplary embodiment of a damper 250 isillustrated in FIG. 2. The damper 250 may be inserted and secured in theclosed end 208 of the first annular tube 204 by corresponding threadedconnections. Various embodiments of a damper that could be incorporatedinto a suspension system may be seen in FIGS. 3-14. Any of thesestructures could be substituted for the damper 250 illustrated in FIG.2.

Turning now to the embodiment of FIG. 3, one embodiment of a damper 250is illustrated in greater detail. The first annular tube 204 may definea compression chamber 228 and a damping chamber 324. The piston 224 mayslidingly interfit with the first annular tube 204 and may be capable ofcompressing a compressible gas in the compression chamber 228.

The damper 250 may be incorporated into the first annular tube 204. Athread 302 may be incorporated on an inner surface 304 of the firstannular tube 204. A corresponding thread 306 may be incorporated onto anexterior surface 308 of the head 310 of the damper 250. When the damper250 is assembled with the first annular tube 204, the head 310 of thedamper 250 may form the closed end 208 of the first annular tube 204. Afirst end 316 of a shaft 312 may thereby be attached or connected to andextend from the closed end 208 of the first annular tube 204. The shaft312 may be annular along at least a portion of its length. A barrierassembly 314 may be attached to a second end 318 of the shaft 312. Insome embodiments, the shaft 312 may include a first corresponding thread320 and the barrier assembly 314 may include a second correspondingthread 322. The first corresponding thread 320 and the secondcorresponding thread 322 may be configured to mate with one another toallow the attachment of the barrier assembly 314 to the shaft 312. Thebarrier assembly 314 may at least partially define a boundary betweenthe compression chamber 228 and the damping chamber 324. The compressionchamber 228 may be on one side 372 of the barrier assembly 314 and thedamping chamber 324 may be on another, opposite side 374 of the barrierassembly 314. In many embodiments, the damper 250 may be positionedwithin the first annular tube 204 remote from the movable pistonassembly 216. In many embodiments, the barrier assembly 314 may bepositioned near the first end 208 of the first annular tube 204.

In some embodiments, the barrier assembly 314 may include a dampingbarrier 326 and a damping seal 328. The barrier assembly 326 may bedesigned to restrict or control the passage of compressed gas betweenthe compression chamber 228 and the damping chamber 324. In manyembodiments, because the damping barrier 326 may be configured to remainsubstantially stationary within the first annular tube 204, the dampingseal 328 may be unnecessary and the damping barrier 326 may be designedto interfit with the first annular tube 204 with a tight tolerance. Inother embodiments, it may be desirable for the damping barrier 326 tohave a smaller diameter than the diameter of the first annular tube 204.The damping seal 328 may be configured to bridge the distance betweenthe diameter of the damping barrier 326 and the diameter of the firstannular tube 204. Such a damping seal 328 is conventional and may beselected by a person having ordinary skill in the art in a known mannerbased, at least in part, on manufacturing tolerances, size, and thedesired pressure of the pressurized gas within the first annular tube204 and the second annular tube 206.

The damper 250 may include a first valve 330 and a second valve 340. Thefirst valve 330 may be positioned operatively between and mayselectively permit compressed gas to flow from the compression chamber228 to the damping chamber 324. The second valve 340 may be positionedoperatively between and may selectively permit compressed gas to flowfrom the damping chamber 324 to the compression chamber 228.

In the embodiment of FIG. 3, the first valve 330 may include a firstpassageway 332 that allows the passage of gas between the compressionchamber 228 and the damping chamber 324. The first passageway 332 may beserpentine. The first passageway 332 may include a plurality ofapertures 333 defined within the shaft 312. In other embodiments, thefirst passageway 332 may include a single aperture defined within theshaft 312. In many embodiments, the first passageway 332 may alsoinclude one or more apertures 370 through the barrier assembly 314. Inthe configuration illustrated in FIG. 3, the first passageway 332 may beconfigured to allow compressed gas to flow from the compression chamber228 through the aperture 370 in the damping barrier, continue throughthe shaft 312, and exit through at least one aperture 333 in the shaft312. A first blocker 334 may be positioned adjacent to or within thefirst passageway 332. In the embodiment shown in FIG. 3, the firstblocker 334 may be a pin. A first bias, such as the spring 336, may bepositioned adjacent the first blocker 334. In many embodiments, thefirst bias 336 may be a coil spring. In other embodiments, it may be aleaf spring or a resilient elastomer. Other biasing elements may also beused, if desired by a designer. In many embodiments, the first bias 336may be configured to bias or urge the first blocker 334 into a closedposition. The first bias 336 may press against a first end 360 of theblocker 334. A second, opposite end 366 of the blocker may impinge on alip or edge 364 within the shaft 312. This configuration may allow thefirst bias 336 to hold the first blocker 334 in a maximally restrictiveposition.

The first blocker 334 may be acted upon by a variety of forces. First,the first blocker 334 may be acted upon by gravity to move or retain thefirst blocker 334 in the lowest possible position. Next, depending onthe position of the first bias 336 and the adjuster 346 (as will bedescribed in greater detail below), the first bias 336 may also exert aforce on the first blocker 334 urging it to its lowest possibleposition. In many embodiments, the cumulative pressure or force of thecompressed gas in the compression chamber 228, damping chamber 324, andin other areas of the suspension unit may exert a downward force on thefirst blocker 334. These forces may combine to form an effective forceapplied to the first blocker 334. In many embodiments, the lowestpossible position of the first blocker 334 may represent a closedposition of the first valve 330, as shown in FIG. 3.

In use, a rider is likely to ride the vehicle over areas of terrain witha variety of obstacles. When a rider encounters an obstacle, thesuspension unit 202 may be configured to absorb at least some of theforce of the impact. In such an instance, the movable piston assembly216 may move upwardly within the first annular tube 204. This movementmay serve to compress the compressible gas within the compressionchamber 228. In some instances, the force of the compressible gas in thecompression chamber 228 may function as in a conventional suspension.However, in other instances, the compression of the compressible gas mayactuate the damper 250 to damp the compression and reduce shock passingto the rider.

When the piston assembly 216 moves upward, it may compress thecompressible gas in the compression chamber 228. This compression maycreate a pressure or force within the compression chamber 228. When theforce in the compression chamber 228 exceeds a threshold level of force,this threshold level of force may overcome the effective force. Theresult of the threshold level of force overcoming the effective force ismovement of the first blocker 334 upwardly, thereby opening the firstvalve 330 and permitting the compressible gas to flow between thecompression chamber 228 and the damping chamber 324.

Pressure from the compressible gas in the compression chamber 228 mayvariably open the first valve 330. Because a portion of the effectiveforce urging the first blocker 334 into a closed position may be appliedby a spring, such as the spring 336, the effective force, particularlythe effective spring force of the spring 336 may vary, based on thedegree to which the blocker 334 is moved. This is due to well-knownproperties of springs. As the first blocker 334 is more greatlydisplaced upwardly, and the spring 336 is thereby compressed farther,proportionally more force is required to move the blocker 334 upward agreater distance. Accordingly, depending on the spring constant of thebias, varying amounts of force from the compressible gas in thecompression chamber may cause varying degrees of opening of the firstvalve 330. Such choices may improve a rider's feel, by damping thecompression of the suspension unit, particularly upon the application ofa sharp force to the suspension unit. By selecting an appropriate bias336 and an appropriate size of the passageway 332, particularly theholes 333, a person having ordinary skill in the art may appropriatelytune the first valve 330 to open to varying degrees at variousthresholds of force. Such design choices are within the scope of adesigner of ordinary skill in the art.

Further, in some embodiments, the first valve 330 may be configured toallow a user to adjust the damping properties of the damper 250, andmore specifically, the first valve 330. The damper 250 may include anadjuster 346 that may be manipulable by a user from the exterior of thevehicle. In some embodiments, the adjuster 346 may be a knob. In otherembodiments, the adjuster 346 may be a lever. The precise externalconfiguration of the adjuster 346 is not critical to the function of theembodiments. The adjuster 346 may be configured to directly orindirectly interact with the first bias 336 to reduce the force exertedby the first bias 336 by changing the preload on the bias 336. How theadjuster 346 may perform this function may be seen by a comparison ofFIGS. 3, 4, and 5. In the embodiment shown in FIG. 3, when the adjuster346 is rotated, the upper portion 348 of the shaft 312 may also rotate.This rotation will cause longitudinal displacement in or out (dependingon the direction of rotation) of a pin 350. When the pin 350 isdisplaced upwardly (in the orientation shown in FIG. 3), the first bias336 is permitted to expand, reducing the preload of the first bias 336.Such a position is shown in FIG. 4 at a first extreme position 401 ofthe adjuster 346. In some embodiments, the adjuster may be configured topresent a gap, such as the gap 403, between the pin 350 and the firstbias 336. In such an embodiment, the threshold force in the compressionchamber 228 to at least slightly open the passageway 332 and allowcompressible gas to flow between the compression chamber 228 and thedamping chamber 324 may be very low. As was the case in the intermediateadjuster position of FIG. 3, as the first blocker 334 is displacedupwardly, it may contact the first bias 336, thereby requiringadditional increase in force in the compression chamber 228 foradditional incremental increase in the displacement of the first blocker334.

A second extreme position 505 of the adjuster 346 may be seen in FIG. 5.At this second extreme position, the pin 350 may be displaced downwardly(in the orientation shown in FIG. 4). In such a position, the first bias336 is more greatly compressed relative to the intermediate position ofthe adjuster 346 as shown in FIG. 3, thereby increasing the preload ofthe first bias 336. The change of the spring preload of the first bias336 may thereby change the pressure necessary to move the first blocker334 and allow the passage of the compressed gas through the firstpassageway 332. In many embodiments, while it may be physically possibleto increase the preload to prevent the blocker 334 from being able to bedisplaced and allow passage of compressed gas between the compressionchamber 228 and the damping chamber 324, in most embodiments, such aconfiguration may be undesirable, as it would merely reduce theeffective size of the compression chamber 228, which may have a negativeeffect on ride feel. Accordingly, it may be desirable in manyembodiments to allow adjustment only to an extent that a rider can onlymaximally adjust the adjuster 346 to allow the opening of the firstvalve 330 in extreme forces.

In many of the embodiments shown, and as most clearly shown in theembodiments of FIGS. 3-5, the adjuster 346 may be adjustable between atleast three positions. In a first extreme position, such as firstextreme position 401, the preload on the first bias 336 may be minimizedor eliminated, possibly even allowing for free movement of the firstblocker 334 for some distance. That is, in some embodiments, theeffective force may be only the force necessary to overcome the force ofgravity on the first blocker 334. In such a first extreme position 401,the first valve 330 substantially allows the flow of compressed gas fromthe compression chamber 228 to the damping chamber 324, relative to theother positions of the adjuster 346. In a second extreme position, suchas second extreme position 505, the preload on the first bias 336 may beincreased. In such an embodiment, the free end 366 of the blocker 334may be pressed against the lip 362. Once such impact is made, thepreload on the first bias 336 may increase. In such a second extremeposition 505, the first valve 330 substantially restricts the flow ofcompressed gas from the compression chamber 228 to the damping chamber324, relative to the other positions of the adjuster 346. In a third,intermediate position, such as that shown in FIG. 3, the preload on thefirst bias 336 may be intermediate that of the two extreme positions. Insuch a third position, the first valve 330 partially restricts the flowof compressed gas from the compression chamber 228 to the dampingchamber 324, relative to the extreme positions of the adjuster 346described above.

FIG. 6 illustrates a top view of one embodiment of an adjuster 346. Inthis exemplary embodiment, the adjuster 346 may include a lever 607 thatis manipulable by a user. The position of the lever 607 as shown in FIG.6 may be the intermediate position of the adjuster 346 as illustrated inFIG. 3. The first extreme position 401 and the second extreme position505 are illustrated in dashed lines. In some embodiments, indicia, suchas the dots 609 shown, may be used to assist a user in understanding therange of possible adjustment. In many embodiments, the adjuster 346 maybe infinitely adjustable between the first extreme position 401 and thesecond extreme position 505. In other embodiments, the adjuster may berestricted to only certain intermediate positions, such as those shownas dots 609 in FIG. 6. A person having ordinary skill in the art mayselect an appropriate structure and method for allowing such adjustment.For many riders, having the maximum control over adjustments isdesirable, so in many embodiments, a designer is likely to select aninfinite adjustment range.

A further embodiment showing a different function of the adjuster may beseen in FIG. 7. In such an embodiment, the longitudinal displacement ofthe pin 350 may be used to adjust the position of the first blocker 334within the passageway 332. In the embodiment illustrated in FIG. 7, thepin 350 may be secured to one end 709 of the first bias 336. The firstblocker 334 may be secured to the other end 711 of the first bias 336.As the pin is displaced upwardly, the upward spring force on the blocker334 from the first bias 336 may move the blocker 334 within thepassageway 332, and relative to the openings 333 in the shaft 312. Aswill be understood by a person having ordinary skill in the art,adjusting the position of the free end 366 relative to the openings 333and the lip 362 without the free end 366 making contact with the lip 362may change the threshold amount of force in the compression chambernecessary to variably open the first valve 330. Other structures areavailable to adjust the position of the first blocker 334 integrallywith the first bias 336, and such structures are well known todesigners. The version shown in FIG. 7 is merely illustrative of onesimplified possible structure.

In the embodiments that follow, it will be understood by a person havingordinary skill in the art that the effective force on the respectivebiases may be adjusted in a manner similar to that shown in FIGS. 3-6.When the use of an adjuster is mentioned, it will be understood that theadjuster may be used in a similar manner. In embodiments where it ismeaningful, a free end of a blocker may be adjustable within thepassageway. In embodiments where it is meaningful, a preload of a biasmay be reduced or increased. The illustrated embodiments will beunderstood by a person having ordinary skill in the art to show anintermediate position of the adjuster. Such a designer will be able toconfigure each additional embodiment to allow for a range of effectiveforces to allow the variable opening of the passageway to allowcompressible gas between the compression chamber and the damping chamberwithout undue experimentation.

Returning to the embodiment of FIG. 3, the damper 250 may furtherinclude a second valve. The second valve 340 may include a secondpassageway 338 that allows the passage of gas between the compressionchamber 228 and the damping chamber 324. The second passageway 338 maybe a plurality of apertures defined within the damping barrier 326. Inother embodiments, the second passageway 338 may be a single aperturedefined within the damping barrier 326. In other embodiments, the secondpassageway 338 may be defined within the shaft 312. A second blocker 342may be positioned adjacent the second passageway 338 and may beconfigured to selectively open and close to restrict or control the flowof compressed gas from the damping chamber 324 to the compressionchamber 228. In the embodiment shown in FIG. 3, the second blocker 342may be a shim, and in particular may be a flexible shim. If a flexibleshim is used, the flexible shim may function as an additional bias, dueto its ability to deform under pressure. If such a shim is used, aperson having ordinary skill in the art will understand that when thesecond bias is described herein, it will be understood to incorporatethe properties of the shim therein. A second bias, such as the spring344, may be positioned adjacent the second blocker 342 to define theproperties under which the second blocker 342 may move to its openposition. In many embodiments, the second bias 344 may be a coil spring.In other embodiments, it may be a leaf spring or a resilient elastomer.Other biasing elements may also be used, if desired by a designer. Inmany embodiments, the second bias 344 may be configured to bias or urgethe second blocker 342 into a closed position.

The embodiments of FIGS. 8-14 share many elements in common with theembodiments of FIG. 3. The function of the embodiments is substantiallythe same. Many of the structural elements are substantially the same asthose in FIG. 3. Only where there is a difference is the differencedescribed. In addition, most of the design changes between theconfigurations can be mixed and matched. For example, the design of thefirst valve in the embodiment of FIG. 3 could be substituted into theconfiguration of many of the other FIGS. without making any othersubstitutions. A person having ordinary skill in the art will be able tomake such changes without undue experimentation.

The differences between the damper of FIG. 3 and that of FIGS. 8-14 maybe seen most clearly in the detailed view of FIG. 8. In the damper 800,there are changes to both the first valve 802 and the second valve 804.In the first valve 802, the blocker may be a ball 806. Upwarddisplacement of the ball 806 functions in a manner similar to theblocker 334 to allow compressed gas to pass between the compressionchamber 828 and the damping chamber 830 through the first passageway808. The first valve 802 or portions thereof may be adjustable by theadjuster 810.

The embodiment of FIG. 8 also includes changes to the second valve 804.In the FIG. 8 embodiment, the second blocker 816 may be an elastomericor compressible o-ring trapped by a retaining ring 818 forming a lip. Insuch an embodiment, the second blocker 816 also functions as a bias.Pressure from the compressed gas within the damping chamber 830 maycompress the second blocker 816 and move it away from the secondpassageway 820. This compression may allow the passage of the compressedgas through the second passageway 820 and around the second blocker 816into the compression chamber 828. When sufficient gas has been releasedfrom the damping chamber 830, the internal biasing of the second blocker816 may force the second blocker 816 into a sealing relationship to thesecond passageway 820, thereby substantially preventing the flow of thecompressed gas between the damping chamber 830 and the compressionchamber 828.

Turning now to the embodiment of FIG. 9, the damper 900 includes adifferent combination of features to form the first damping valve 902and the second damping valve 904. The first damping valve 902 issubstantially the same as that disclosed as the first damping valve 802of FIG. 8. The second damping valve 904 is substantially the same asthat disclosed as the second damping valve 340 shown in FIG. 3. Thisembodiment demonstrates, among other things, that various elements fromthe different embodiments may be combined differently to form equallyfunctional shock absorbers. The first valve 902 or portions thereof maybe adjustable by the adjuster 906.

Turning now to FIG. 10, the damper 1000 may include a first valve 1002and a second valve 1004 that allow gas to pass between the compressionchamber 1006 and the damping chamber 1008. The second valve 1004 may besubstantially the same as that described in the embodiments of FIG. 3 orFIG. 9, and accordingly a description of the second valve 1004 will notbe repeated here.

However, the first valve 1002 shows a first blocker 1010 that isself-biasing. In the FIG. 10 embodiment, the first blocker 1010 may bean elastomeric or compressible pin made of a resilient material. In suchan embodiment, the first blocker 1010 may also function as a bias.Pressure from the compressed gas within the compression chamber 1006 maycompress and/or move the first blocker 1010 upwardly within the firstpassageway 1012. This compression may allow the passage of thecompressed gas through the first passageway 1012 between the compressionchamber 1006 and the damping chamber 1008. When sufficient gas has beenreleased from the compression chamber 1006, the internal biasing of thefirst blocker 1010 may return the first blocker 1010 into its initialposition, thereby substantially restricting or preventing the flow ofthe compressed gas from the compression chamber 1006 to the dampingchamber 1008.

In the embodiment of FIG. 10, the adjuster 1014 may be configured toseat and press directly against a first end 1016 of the self-biasingblocker 1010. The adjuster 1014 may be configured to increase ordecrease the pressure between the opposite, second end 1018 of theself-biasing blocker 1010 against the lip or edge 1020 on the interiorof the shaft 1022. This increase and decrease in pressure may varypreload of the self-biasing blocker 1010, thereby adjusting the dampingof the suspension unit. The adjuster 1014 may also, or alternatively, becapable of adjusting the position of the second end 1018 relative to thelip 1020, such that the second end 1018 of the blocker 1010 is spacedfrom the lip 1020. This adjustment of the self-biasing blocker 1010 isthe same in principle to that illustrated and described above. Thissubstitution is apparent to a person having ordinary skill in the art.

Turning now to the embodiment of FIG. 11, the first valve 1102 and theadjuster 1103 are substantially identical to the embodiment of FIG. 10,and thus the first valve 1102 will not be described further. The secondvalve 1104 is similar in principle to that illustrated as second valve804 in FIG. 8. However, in the embodiment of FIG. 11, the constructionof the barrier assembly 1106 is simplified to allow for theincorporation of the second valve 1104. The central bore 1108 of thebarrier assembly 1106 may be enlarged to allow passage of the shaft 1110with a gap 1120 between the shaft 1110 and the bore 1108. An o-ring 1112may be positioned against a flange 1114 on a threaded bolt securing thebarrier assembly 1106 in position on the shaft 1110. When the pressurein the damping chamber 1116 exceeds that in the compression chamber1118, compressible gas may flow into the gap 1120 between the shaft 1110and the bore 1108. The pressure from the compressible gas may compressthe o-ring 1112, thereby opening the second valve 1104 and permittingcompressible gas to flow between the damping chamber 1116 and thecompression chamber 1118.

The use of the adjuster in connection with a resilient blocker may beapparent when a comparison is made between FIG. 10 and FIG. 11. As maybe seen in FIG. 11, the adjuster 1103 may be positioned in a firstextreme position. In such a position, the adjuster 1103 may be moved todisplace the resilient blocker 1124 upwardly, creating a gap 1130between a lower end 1126 of the blocker 1124 and the lip 1128. In someembodiments, the lip 1128 may be spaced from the apertures 1132 definedwithin the shaft 1110, thereby allowing for a gap 1130 between the lip1128 and the lower end 1126 of the blocker 1124. In some embodiments,such as the one illustrated in FIG. 11, the adjuster 1103 may beconfigured to position the blocker 1124 such that the aperture 1132 isat least partially open, allowing for some flow of compressed gasbetween the compression chamber 1118 and the damping chamber 1116. Thismay represent a first extreme position of the adjuster 1104. In manyembodiments, it may be desirable for the first extreme position to onlyallow for a comparatively small opening of the aperture 1132 andtherefore passageway 1122. In such a configuration, an increase inpressure in the compression chamber 1118 may compress the resilientblocker 1124, thereby moving the lower end 1126 of the blocker 1124upwardly, thereby variably increasing the size of the passageway 1122based on the pressure in the compression chamber 1118 and the pressuredifference between the compressible gas in the compression chamber 1118relative to the damping chamber 1116.

Looking now at the embodiment of FIG. 10, the adjuster 1014 may be in asecond extreme position or an intermediate position. Which position itis in would be difficult to discern from this view. In a second extremeposition, the adjuster 1014 would be turned so that the lower end 1018of the blocker 1010 is pressed against the lip 1020 to a designatedmaximum degree. The compression of the resilient blocker 1010 mayincrease the effective spring force of the first valve 1002. In thissecond extreme position, only when the force in the compression chamber1006 rises a great deal is the resilient blocker 1010 likely to furthercompress and open the passageway 1012. In an intermediate position ofthe adjuster 1014, the lower end 1018 may just touch the lip 1020,thereby requiring some increase in force of the compressed gas in thecompression chamber 1006 to compress the resilient blocker 1010, causingthe lower end 1018 to move upwardly and open the passageway 1012.

Accordingly, the embodiments of FIGS. 10 and 11 are, in this way,similar to the embodiment shown in FIGS. 3-5. The adjuster 1014, 1103may be adjustable between at least three positions. In a first extremeposition, the preload on the first blocker 1010, 1124 may be minimizedor eliminated, possibly even allowing the passageway 1012, 1122 toremain partially open. In such a first extreme position, the first valve1002, 1102 substantially allows the flow of compressed gas from thecompression chamber 1006, 1118 to the damping chamber 1008, 1116,relative to the other positions of the adjuster 1014, 1103. In a secondextreme position, the preload on the first blocker 1010, 1124 may beincreased. In such an embodiment, the free end 1018, 1126 of the firstblocker 1010, 1124 may be pressed against the lip 1020, 1128. Once suchimpact is made, the preload on the first blocker 1010, 1124 mayincrease. In such a second extreme position, the first valve 1002, 1102may substantially restrict the flow of compressed gas from thecompression chamber 1106, 1118 to the damping chamber 1008, 1116,relative to the other positions of the adjuster 1014, 1103. In a thirdintermediate position, the preload on the first blocker 1010, 1124 maybe intermediate that of the two extreme positions. In such a thirdposition, the first valve 1002, 1102 may partially restrict the flow ofcompressed gas from the compression chamber 1106, 1118 to the dampingchamber 1008, 1116, relative to the other positions of the adjuster1014, 1103. The features of the adjuster 346, particularly as shown inFIG. 6, may also be used in this detailed embodiment. For example, theadjuster may be infinitely adjustable between the three describedpositions.

In addition, it will be apparent to a person having ordinary skill inthe art that there are a variety of ways and structures that will allowfor a similar adjustment function. For example, instead of moving theblocker or bias, the adjuster could be configured to adjust the shaftand the apertures therein relative to the blocker or bias. In anotherembodiment, the adjuster could be configured to adjust the position ofthe lip. In other embodiments, each of these features could beindependently adjustable with its own adjuster. Further configurationshaving a similar result may be contemplated by a person having ordinaryskill in the art and may fall within the scope of the presentdisclosure. In such configurations, in addition to the embodimentsdescribed in greater detail above, the adjuster may adjust one or moreparts of the valve and may be considered to “adjust the valve” to allowfor a variety of air passage results. In each embodiment, such anadjuster may be adjustable between at least three positions. In a firstextreme position, the adjuster may adjust the first valve tosubstantially allow the flow of compressed gas from the compressionchamber to the damping chamber, relative to the other positions of theadjuster. In a second extreme position, the first valve maysubstantially restrict the flow of compressed gas from the compressionchamber to the damping chamber, relative to the other positions of theadjuster. In a third intermediate position, the preload on the firstblocker may be intermediate that of the two extreme positions. In such athird position, the first valve may partially restrict the flow ofcompressed gas from the compression chamber to the damping chamber,relative to the other positions of the adjuster. As noted above, theadjuster may be infinitely adjustable between these three positions.

Turning now to the embodiment of FIG. 12, it will be apparent that thebarrier assembly and valves may take a variety of forms. In FIG. 12, yetanother embodiment of a damper 1250 analogous to damper 250 of FIG. 2 isillustrated in greater detail. The first annular tube 1204 may define acompression chamber 1206 and a damping chamber 1208. The piston 1210 mayslidingly interfit with the first annular tube 1204 and may be capableof compressing a compressible gas in the compression chamber 1206.

The damper 1250 may be incorporated into the first annular tube 1204remote from the piston 1210. A thread 1212 may be incorporated on aninner surface 1214 of the first annular tube 1204. A correspondingthread 1216 may be incorporated onto an exterior surface 1218 of thehead 1220 of the damper 1250. When the damper 1250 is assembled with thefirst annular tube 1204, the head 1220 of the damper 1250 may form theclosed end of the first annular tube 1204. A barrier assembly 1222 mayinclude a thread 1224 and may further be attached to the first annulartube 1204 near an end of the annular tube 1204 by using the thread 1212on the inner surface 1214 of the first annular tube 1204. In such aconfiguration, a seal between the barrier assembly 1222 and the firstannular tube 1204 may be less important. The barrier assembly 1222 maybe designed to restrict or control the passage of compressed gas betweenthe compression chamber 1206 and the damping chamber 1208. Thecompression chamber 1206 may be on one side 1223 of the barrier assembly1222 and the damping chamber 1208 may be on another, opposite side 1225of the barrier assembly 1222.

The damper 1250 may include a first valve 1226 and a second valve 1228.The first valve 1226 may be positioned operatively between and mayselectively permit compressed gas to flow from the compression chamber1206 to the damping chamber 1208. The second valve 1228 may bepositioned operatively between and may selectively permit compressed gasto flow from the damping chamber 1208 to the compression chamber 1206.

In the embodiment of FIG. 12, the first valve 1226 may include a firstpassageway or aperture 1230 through the barrier assembly 1222 thatallows the passage of gas between the compression chamber 1206 and thedamping chamber 1208. In the configuration illustrated in FIG. 12, thefirst passageway 1230 may be configured to allow compressed gas to flowfrom the compression chamber 1206 through the aperture 1230 in thebarrier assembly 1222 to the damping chamber 1208.

A first blocker 1232 may be positioned adjacent to or within the firstpassageway 1230. In the embodiment shown in FIG. 12, the first blocker1232 may be a frustoconical pin or plate that may have a similar shapeand size to the passageway 1230. A first bias, such as the spring 1234,may be positioned adjacent the first blocker 1232. In many embodiments,the first bias 1234 may be a coil spring. In other embodiments, it maybe a leaf spring or a resilient elastomer. Other biasing elements mayalso be used, if desired by a designer. In many embodiments, the firstbias 1234 may be configured to bias or urge the first blocker 1232 intoa closed position. The first bias 1234 may press against a first end orside 1236 of the first blocker 1232. A second, opposite end or side 1238of the blocker may interfit with the first passageway 1230. Thisconfiguration may allow the first bias 1234 to hold the first blocker1232 in a maximally restrictive position.

The first blocker 1232 may be acted upon by a variety of forces. First,the first blocker 1232 may be acted upon by gravity to move or retainthe first blocker 1232 in the lowest possible position. Next, dependingon the position of the first bias 1234 and the adjuster 1240, the firstbias 1234 may also exert a force on the bias urging it to its lowestpossible position. In many embodiments, the cumulative pressure or forceof the compressed gas in the compression chamber 1206, damping chamber1208, and in other areas of the suspension unit may exert a downwardforce on the first blocker 1232. These forces may combine to form aneffective force applied to the first blocker 1232. In many embodiments,the lowest possible position of the first blocker 1232 may represent aclosed position of the first valve 1226, as is the case in FIG. 12.

When the piston assembly 1210 moves upward, it compresses thecompressible gas in the compression chamber 1206. This compressioncreates a pressure or force within the compression chamber 1206. Whenthe force in the compression chamber 1206 exceeds a threshold level offorce, this threshold level of force may overcome the effective force.This may move the first blocker 1232 upwardly, thereby opening the firstvalve 1226 and permitting the compressible gas to flow between thecompression chamber 1206 and the damping chamber 1208. In manyembodiments, the compressible gas may primarily flow from thecompression chamber 1206 through the passageway 1230 and into thedamping chamber 1208.

Pressure from the compressible gas in the compression chamber 1206 mayvariably open the first valve 1226. Because a portion of the effectiveforce urging the first blocker 1232 into a closed position may beapplied by a spring, such as the spring 1234, the effective force,particularly the effective spring force of the spring 1234 may vary,based on the degree to which the blocker 1232 is moved. This is due towell-known properties of springs. As the first blocker 1232 is moregreatly displaced upwardly (in the orientation of FIG. 12),proportionally more force is required to move the blocker 1232 upward agreater distance. Accordingly, depending on the spring constant of thebias, varying amounts of force from the compressible gas in thecompression chamber may cause varying degrees of opening of the firstvalve 1226. Such choices may improve a rider's feel, by damping thecompression of the suspension unit, particularly upon the application ofa sharp force to the suspension unit. By selecting an appropriate biasand an appropriate size of the passageway 1230, a person having ordinaryskill in the art may appropriately tune the first valve 1226 to open tovarying degrees at various thresholds of force. Such design choices arewithin the scope of a designer of ordinary skill in the art.

Further, in some embodiments, the first valve 1226 may be configured toallow a user to adjust the damping properties of the damper 1250, andmore specifically, the first valve 1226. The damper 1250 may include anadjuster 1240 that may be manipulable by a user from the exterior of thevehicle. In the embodiment shown in FIG. 12, the adjuster 1240 is aknob, but may take alternative configurations known by a person havingordinary skill in the art.

The structure and function of the adjuster in FIG. 12 is similar to thatin FIGS. 3-7. In the embodiment illustrated in FIG. 12, rotation of theadjuster 1240 may raise or lower a plate 1242. One end 1246 of the firstbias 1234 may be in contact with or secured to the plate 1242. The otherend 1248 of the first bias 1234 may be in contact with or secured to thefirst blocker 1232. If the first bias 1234 is secured to each of theplate 1242 and the first blocker 1232, as the first blocker 1232 isdisplaced upwardly through rotation of the adjuster 1240, the upwardspring force on the first blocker 1232 from the first bias 1234 may movethe first blocker 1232 within and away from the passageway 1230. Such anupward movement may allow the first blocker 1232 to be positioned toallow the first valve 1226 to remain partially open, with a similarresult to that shown and described in connection with FIG. 11. Similarlyto the embodiment of FIGS. 3-5, when the adjuster 1240 is rotated tomove the plate 1242 downwardly, the first bias 1234 may be compressedand may press the first blocker 1232 more tightly against the firstpassageway 1230. When a knob is used as the adjuster 1240, it may bedesirable to use a circular bias and first blocker in the event thatrotational force is transmitted to the bias and/or the blocker. Theremaining features, consequences, and implications of similar adjustmentstructures have been described in sufficient detail in connection withthe prior FIGS. and will not be repeated here. A person having ordinaryskill in the art will understand how to make appropriate substitutionsto achieve similar results in the present embodiment.

In the embodiment of FIG. 12, the damper 1250 may further include asecond valve 1228. The second valve 1228 may include a second passageway1252 that allows the passage of gas between the compression chamber 1206and the damping chamber 1208. The second passageway 1252 may be aplurality of apertures defined within the barrier assembly 1222. Inother embodiments, the second passageway 1252 may be a single aperturedefined within the damping barrier 1222. A second blocker 1254 may bepositioned adjacent the second passageway 1252 and may be configured toselectively open and close to restrict or control the flow of compressedgas from the damping chamber 1208 to the compression chamber 1206. Inthe embodiment shown in FIG. 12, the second blocker 1254 may be aresilient or elastomeric band. In such a configuration, the secondblocker 1254 may also serve as the second bias. In many embodiments, thesecond bias is configured to bias or urge the second blocker 1254 into aclosed position. The second valve 1228 may be configured such that whenthe force or pressure within the damping chamber 1208 exceeds that inthe compression chamber 1206 by a threshold force, that pressure maydeform the second blocker 1254, thereby opening the second valve 1228and allowing compressed gas to pass between the damping chamber 1208 andthe compression chamber 1206.

In some of the embodiments above, it was described that the firstblocker could be positioned to keep the first valve in a position wherethe valve was partially open. Such a configuration in the aboveembodiments was often a function of the position of the adjuster. In theembodiments described above, the valve could be adjusted to require somethreshold force to permit air to flow between the compression chamberand the damping chamber. In some embodiments, however, it may bedesirable to allow air passage through a narrow passage between acompression chamber and a damping chamber, with a first valveincorporated to allow for greater airflow upon the application of aforce over a certain threshold to the suspension.

Turning now to the embodiment of FIG. 13, another embodiment of a damper1350 is illustrated in greater detail. The first annular tube 1304 maydefine a compression chamber 1306 and a damping chamber 1308. The piston1310 may slidingly interfit with the first annular tube 1304 and may becapable of compressing a compressible gas in the compression chamber1306.

The damper 1350 may be incorporated into the first annular tube 1304. Athread 1312 may be incorporated on an inner surface 1314 of the firstannular tube 1304. A corresponding thread 1316 may be incorporated ontoan exterior surface 1318 of the head 1320 of the damper 1350. When thedamper 1350 is assembled with the first annular tube 1304, the head 1320of the damper 1350 may form the closed end 1322 of the first annulartube 1304. A first end 1324 of a shaft 1326 may thereby be attached orconnected to and extend from the closed end 1322 of the first annulartube 1304. The shaft 1326 may be annular along at least a portion of itslength. A barrier assembly 1330 may be positioned at a second end 1328of the shaft 1326. The barrier assembly 1330 may at least partiallydefine a boundary between the compression chamber 1306 and the dampingchamber 1308. In many embodiments, the damper 1350 may be positionedwithin the first annular tube 1304 remote from the movable pistonassembly 1310. In many embodiments, the barrier assembly 1330 may bepositioned near the closed end 1322 of the first annular tube 1304.

In some embodiments, the barrier assembly 1330 may include a dampingbarrier 1334 and a damping seal 1332. The barrier assembly 1330 may bedesigned to restrict or control the passage of compressed gas betweenthe compression chamber 1306 and the damping chamber 1308. Thecompression chamber 1306 may be on one side 1333 of the barrier assembly1330 and the damping chamber 1308 may be on another, opposite side 1335of the barrier assembly 1330.

The damper 1350 may include a first valve 1336 and a second valve 1338.The first valve 1336 may be positioned operatively between, and mayselectively permit compressed gas to flow from, the compression chamber1306 to the damping chamber 1308. The second valve 1338 may bepositioned operatively between, and may selectively permit compressedgas to flow from, the damping chamber 1308 to the compression chamber1306.

In the embodiment of FIG. 13, the first valve 1336 may include a firstpassageway 1340 that allows the passage of gas between the compressionchamber 1306 and the damping chamber 1308. The first passageway 1340 maybe serpentine.

A first blocker 1342 may be positioned adjacent to the second end 1328of the shaft 1326. A first bias, such as the spring 1344, may bepositioned adjacent the first blocker 1342. In many embodiments, thefirst bias 1344 may be a coil spring. In other embodiments, it may be aleaf spring or a resilient elastomer. Other biasing elements may also beused, if desired by a designer. In many embodiments, the first bias 1344may be configured to bias or urge the first blocker 1342 into a closedposition. The first bias 1344 may press against a first side 1346 of thefirst blocker 1342. A second, opposite side 1348 of the first blocker1342 may impinge on a lip or edge 1352 extending outwardly from theshaft 1326.

The first blocker 1342 may be acted upon by a variety of forces. First,the first blocker 1342 may be acted upon by gravity to move or retainthe first blocker 1342 in the lowest possible position (in theorientation shown in FIG. 13). Next, depending on the position of thefirst bias 1344, the first bias 1344 may also exert a force on the firstblocker 1342 urging it to its lowest possible position. In manyembodiments, the cumulative pressure or force of the compressed gas inthe compression chamber 1306, damping chamber 1308, and in other areasof the suspension unit may exert a downward force on the first blocker1342. These forces may combine to form an effective force applied to thefirst blocker 1342. In many embodiments, the lowest possible position ofthe first blocker 1342 may represent a closed position of the firstvalve 1336, as is the case in FIG. 13.

In contrast to some of the other embodiments, the embodiment of FIG. 13may include a supplemental passageway 1354 that may permit compressiblegas to flow between the compression chamber 1306 and the damping chamber1308. In the embodiment of FIG. 13, a supplemental variable valve 1356may be incorporated into the damper 1350 to govern whether thesupplemental passageway 1354 is open or closed and the degree to whichit is open. In the embodiment of FIG. 13, a pin 1358 may be positionedwithin the supplemental passageway 1354. In the embodiment shown in FIG.13, the pin 1358 may have a conical tip 1360 that may be configured tomate with a sloped wall 1362 in the supplemental passageway 1354. Whenthe adjuster 1364 is rotated to fully extend the pin 1358, the conicaltip 1360 may meet the sloped wall 1362 in a sealing fashion andsubstantially prevent the flow of compressed gas through thesupplemental passageway 1354. When the adjuster 1364 is rotated in anopposite direction, the conical tip 1360 may separate from the slopedwall 1362 and permit varying amounts of compressed gas to flow throughthe supplemental passageway 1354.

When the piston assembly 1310 moves upward, it may compress thecompressible gas in the compression chamber 1306. This compressioncreates a pressure or force within the compression chamber 1306.Depending on the degree to which the supplemental valve 1356 is open andthe speed and force of compression, the compressed gas may flow from thecompression chamber 1306 to the damping chamber 1308 without actuatingthe first valve 1336. However, when the force in the compression chamber1306 exceeds a threshold level of force, this threshold level of forcemay overcome the effective force. This may move the first blocker 1342upwardly, thereby opening the first valve 1336 and permitting thecompressible gas to flow between the compression chamber 1306 and thedamping chamber 1308 through the first passageway 1340.

Pressure from the compressible gas in the compression chamber 1306 mayvariably open the first valve 1336. Because a portion of the effectiveforce urging the first blocker 1342 into a closed position may beapplied by a spring, such as the spring 1344, the effective force,particularly the effective spring force of the spring 1344 may vary,based on the degree to which the blocker 1342 is moved. This is due towell-known properties of springs. As the first blocker 1342 is moregreatly displaced upwardly, proportionally more force is required tomove the blocker 1342 upward a greater distance. Accordingly, dependingon the spring constant of the bias, varying amounts of force from thecompressible gas in the compression chamber may cause varying degrees ofopening of the first valve 1336. Such choices may improve a rider'sfeel, by damping the compression of the suspension unit, particularlyupon the application of a sharp force to the suspension unit. Byselecting an appropriate bias, a person having ordinary skill in the artmay appropriately tune the first valve 1336 to open to varying degreesat various thresholds of force. Such design choices are within the scopeof a designer of ordinary skill in the art.

In the embodiment of FIG. 13, the damper 1350 may further include asecond valve 1338. The second valve 1338 may include a second passageway1366 that allows the passage of gas between the compression chamber 1306and the damping chamber 1308. The second passageway 1366 may be aplurality of apertures defined within the damping barrier 1334. A secondblocker 1368 may be positioned adjacent the second passageway 1366 andmay be configured to selectively open and close to restrict or controlthe flow of compressed gas from the damping chamber 1308 to thecompression chamber 1306. In the embodiment shown in FIG. 13, the secondblocker 1368 may be a shim, and in particular may be a flexible shim. Asecond bias, such as a resilient bias 1370, may be positioned adjacentthe second blocker 1368 to define the properties under which the secondblocker 1368 may move to its open position. Other biasing elements mayalso be used, if desired by a designer. In many embodiments, the secondbias is configured to bias or urge the second blocker 1368 into a closedposition.

The use of the adjuster 1364 to control the degree of opening of thesupplemental valve 1356 may affect the timing at which the first valve1336 may open. When the adjuster 1364 is adjusted to a first extremeposition, where the conical tip 1360 of the pin 1358 presses against thesloped wall 1362 of the supplemental passageway 1354, air flow throughthe supplemental passageway 1354 may be substantially prevented.Accordingly, upon compression, the pressure or force within thecompression chamber 1306 may rise relatively quickly to the thresholdlevel of force necessary to overcome the effective force and open thefirst valve 1336. When the adjuster 1364 is adjusted to a second extremeposition, where the conical tip 1360 of the pin 1358 is remote from thesloped wall 1362 of the supplemental passageway 1354, upon compression,the compressible gas in the compression chamber 1306 may flow into thedamping chamber 1308 only through the supplemental passageway 1354 andsubstantially equalize pressure on both sides of the first blocker 1342.In such a situation, the first valve 1336 may only open and allowcompressed gas to flow through both the first passageway 1340 and thesupplemental passageway 1354 in instances of rapid compression. If theadjuster 1364 is in an intermediate position, it may allow compressedgas to flow through the supplemental passageway 1354 only in someinstances and through both passageways 1340, 1354 in other instances.Accordingly, while the adjustment of the adjuster 1364 may not affectthe actual effective force, the adjustment of the adjuster 1364 mayinfluence the opening of the first valve 1336. While this descriptionhas been detailed for the function of the first valve 1336, it will beapparent to a person having ordinary skill in the art that the functionof the second valve 1338 may be similarly affected by the use of thesupplemental valve 1356.

A similar configuration may be found in FIG. 14, where anotherembodiment of a damper 1450 is illustrated in greater detail. The firstannular tube 1404 may define a compression chamber 1406 and a dampingchamber 1408. The piston 1410 may slidingly interfit with the firstannular tube 1404 and may be capable of compressing a compressible gasin the compression chamber 1406.

The damper 1450 may be incorporated into the first annular tube 1404. Athread 1412 may be incorporated on an inner surface 1414 of the firstannular tube 1404. A corresponding thread 1416 may be incorporated ontoan exterior surface 1418 of the head 1420 of the damper 1450. When thedamper 1450 is assembled with the first annular tube 1404, the head 1420of the damper 1450 may form the closed end 1422 of the first annulartube 1404. A first end 1424 of a shaft 1426 may thereby be attached orconnected to and extend from the closed end 1422 of the first annulartube 1404. A barrier assembly 1430 may be positioned at a second end1428 of the shaft 1426. The barrier assembly 1430 may define a boundarybetween the compression chamber 1406 and the damping chamber 1408. Inmany embodiments, the damper 1450 may be positioned within the firstannular tube 1404 remote from the movable piston assembly 1410. In manyembodiments, the barrier assembly 1430 may be positioned near the closedend 1422 of the first annular tube 1404. The compression chamber 1406may be on one side 1433 of the barrier assembly 1430 and the dampingchamber 1408 may be on another, opposite side 1435 of the barrierassembly 1430.

The damper 1450 may include a first valve 1436 and a second valve 1438.The first valve 1436 may be positioned operatively between and mayselectively permit compressed gas to flow from the compression chamber1406 to the damping chamber 1408. The second valve 1438 may bepositioned operatively between and may selectively permit compressed gasto flow from the damping chamber 1408 to the compression chamber 1406.

In the embodiment of FIG. 14, the first valve 1436 may include a firstpassageway 1440 that may allow the passage of gas between thecompression chamber 1406 and the damping chamber 1408. The firstpassageway 1440 may be serpentine.

A first blocker 1442 may be positioned adjacent the barrier assembly1430. The first blocker 1442 may be a resilient shim that isself-biasing, so that the first blocker 1442 is also the first bias. Inother embodiments, a separate bias may also be used, if desired by adesigner. In many embodiments, the first blocker 1442 may configured tobias itself into a closed position.

The first blocker 1442 may be acted upon by a variety of forces. First,the first blocker 1442 may be acted upon by gravity to move or retainthe first blocker 1442 in the lowest possible position. Next, the biasin the first blocker 1442 may also exert a force urging it to its lowestpossible position. In many embodiments, the cumulative pressure or forceof the compressed gas in the compression chamber 1406, damping chamber1408, and in other areas of the suspension unit may exert a downwardforce on the first blocker 1442. These forces may combine to form aeffective force applied to the first blocker 1442. In many embodiments,the lowest possible position of the first blocker 1442 may represent aclosed position of the first valve 1436, as is the case in FIG. 14.

In contrast to some of the other embodiments, the embodiment of FIG. 14may include a supplemental passageway 1454 that permits compressible gasto flow between the compression chamber 1406 and the damping chamber1408. In the embodiment of FIG. 14, a supplemental variable valve 1456may be incorporated into the damper 1450 to govern whether thesupplemental passageway 1454 is open or closed and the degree to whichit is open. In the embodiment of FIG. 14, the barrier assembly 1430 maybe configured to be separated from the first annular tube 1404. In theembodiment shown in FIG. 14, the barrier assembly 1430 may have a slopedwall 1458 that may be configured to mate with a sloped wall 1462 on theinner surface 1414 of the first annular tube 1404. When the adjuster1464 is rotated to fully retract the barrier assembly 1430, the slopedwall 1458 of the barrier assembly 1430 may meet the sloped wall 1462 ofthe first annular tube 1404 in a sealing fashion and substantiallyprevent the flow of compressed gas through the supplemental passageway1454. When the adjuster 1464 is rotated in an opposite direction, thebarrier assembly 1430 may separate from the annular tube 1404 and permitvarying amounts of compressed gas to flow through the supplementalpassageway 1454.

When the piston assembly 1410 moves upward, it may compress thecompressible gas in the compression chamber 1406. This compressioncreates a pressure or force within the compression chamber 1406.Depending on the degree to which the supplemental valve 1456 is open andthe speed and force of compression, the compressed gas may flow from thecompression chamber 1406 to the damping chamber 1408 without actuatingthe first valve 1436. However, when the force in the compression chamber1406 exceeds a threshold level of force, this threshold level of forcemay overcome the effective force. This may move the first blocker 1442upwardly, thereby opening the first valve 1436 and permitting thecompressible gas to flow between the compression chamber 1406 and thedamping chamber 1408 through the first passageway 1440.

Pressure from the compressible gas in the compression chamber 1406 mayvariably open the first valve 1436. Because a portion of the effectiveforce urging the first blocker 1442 into a closed position may beapplied by a bias, the effective force, particularly the effectivespring force of the bias may vary, based on the degree to which theblocker 1442 is moved. This is due to well-known properties of biases.As the first blocker 1442 is more greatly displaced upwardly,proportionally more force is required to move the blocker 1442 upward agreater distance. Accordingly, depending on the spring constant of thebias, varying amounts of force from the compressible gas in thecompression chamber may cause varying degrees of opening of the firstvalve 1436. Such choices may improve a rider's feel, by damping thecompression of the suspension unit, particularly upon the application ofa sharp force to the suspension unit. By selecting an appropriate bias,a person having ordinary skill in the art may appropriately tune thefirst valve 1436 to open to varying degrees at various thresholds offorce. Such design choices are within the scope of a designer ofordinary skill in the art.

In the embodiment of FIG. 14, the damper 1450 may further include asecond valve 1438. The second valve 1438 may include a second passageway1466 that allows the passage of gas between the compression chamber 1406and the damping chamber 1408. The second passageway 1466 may be aplurality of apertures defined within the damping barrier 1434. A secondblocker 1468 may be positioned adjacent the second passageway 1466 andmay be configured to selectively open and close to restrict or controlthe flow of compressed gas from the damping chamber 1408 to thecompression chamber 1406. In the embodiment shown in FIG. 14, the secondblocker 1468 may be a shim, and in particular may be a flexible shim. Asecond bias, such as a resilient bias 1470, may be positioned adjacentthe second blocker 1468 to define the properties under which the secondblocker 1468 may move to its open position. Other biasing elements mayalso be used, if desired by a designer. In many embodiments, the secondbias is configured to bias or urge the second blocker 1468 into a closedposition.

The use of the adjuster 1464 to control the degree of opening of thesupplemental valve 1456 may affect the timing at which the first valve1436 may open. When the adjuster 1464 is adjusted to a first extremeposition, where the sloped wall 1458 of the barrier assembly 1430presses against the sloped wall 1462 of the first annular tube 1404, airflow through the supplemental passageway 1454 may be substantiallyprevented. Accordingly, upon compression, the pressure or force withinthe compression chamber 1406 may rise relatively quickly to thethreshold level of force necessary to overcome the effective force andopen the first valve 1436. When the adjuster 1464 is adjusted to asecond extreme position, where the sloped wall 1458 of the barrierassembly 1430 is remote from the sloped wall 1462 of the first annulartube 1404, upon compression, the compressible gas in the compressionchamber 1406 may flow into the damping chamber 1408 and substantiallyequalize pressure on both sides of the first blocker 1442. In such asituation, the first valve 1436 may only open and allow compressed gasto flow through both the first passageway 1440 and the supplementalpassageway 1454 in instances of rapid compression. If the adjuster 1464is in an intermediate position, it may allow compressed gas to flowthrough the supplemental passageway 1454 only in some instances andthrough both passageways 1440, 1454 in other instances. Accordingly,while the adjustment of the adjuster may not affect the actual effectiveforce, the adjustment of the adjuster may influence the opening of thefirst valve 1436. While this description has been detailed for thefunction of the first valve 1436, it will be apparent to a person havingordinary skill in the art that the function of the second valve 1438 maybe similarly affected by the use of the supplemental valve 1456.

The above embodiments have been described in connection with a frontfork or suspension. In some instances, the embodiments above could beincorporated into a rear shock. However, because of the length of theaverage compression stroke in a rear shock is shorter than that in afront fork, use of an inline system may be less desirable. Accordingly,additional modifications may be desirable when adapted for a rear shock.A person having ordinary skill in the art could, however, choose to usea design illustrated for use in a rear shock in a front fork or viceversa, if such a designer wished.

FIG. 15 illustrates a suspension system 1500 for a vehicle (not shown).The embodiments shown are illustrated in the context of a bicycle.However, the designs could be modified for use with a vehicle havingmore than two wheels or a vehicle powered by a motor. The top end 1502of the suspension system may be directly or indirectly attached avehicle frame (not shown) in a typical manner. The bottom end 1504 ofthe suspension system 1500 may be directly or indirectly attached to avehicle wheel (not shown) in a typical manner.

In the embodiment shown in FIG. 15, the details of a typical suspensionsystem may not be illustrated in detail. Such structures are well-knownby persons of ordinary skill in the art. The structures shown are merelyexemplary. Other structures currently known or developed in the futurecould be substituted therefor by a person of ordinary skill in the artwithout undue experimentation.

The suspension system 1500 may include a first annular tube 1506. Thefirst annular tube 1506 may have a first closed end 1508 at the top ofthe first annular tube 1506 and second closed end 1510 at the bottom ofthe first annular tube 1506. The space defined within the first annulartube 1506 may be at least partially filled with one or more compressiblegases. In many configurations, the first annular tube 1506 may besubstantially round in cross-sectional configuration.

A movable piston assembly 1512 may be attached to the bottom end 1504.In the embodiment shown, the movable piston assembly 1512 may beattached to one end 1516 of a shaft 1518. A second, opposing end 1520 ofthe shaft 1518 may be attached to the bottom end 1504. Such aconfiguration is not required, but in many embodiments it may be anefficient design. The length of the shaft 1518 may be determined basedon the length, circumference, and volume of the first annular tube 1506based on conventional calculations.

The movable piston assembly 1512 may include a movable piston 1522 andan optional seal 1524. The movable piston assembly 1512 may be designedto prevent or minimize the passage of compressed gas between acompression chamber 1526 and a lower chamber 1528. In many embodiments,because the movable piston 1522 is configured to move, it may bedesirable for the movable piston 1522 to have a smaller diameter thanthe inner diameter of the first annular tube 1506. The seal 1524 may beconfigured to bridge the distance between the diameter of the movablepiston 1522 and the diameter of the first annular tube 1506. Such a seal1524 is conventional and may be selected by a person having ordinaryskill in the art in a known manner based, at least in part, onmanufacturing tolerances, size, and the desired pressure of thepressurized gas within the first annular tube 1506. The piston assembly1512, shaft 1518, and much of the remainder of the suspension system aremerely shown and described generally and schematically. Other suspensionstructures could be easily substituted therefor.

A damper 1550 may be incorporated near the first closed end 1508 of thefirst annular tube 1506. The first annular tube 1506 may define acompression chamber 1526 and a damping chamber 1528. The piston 1522 mayslidingly interfit with the first annular tube 1506 and may be capableof compressing a compressible gas in the compression chamber 1526.

The damper 1550 may be incorporated into the first annular tube 1506. Abarrier assembly 1530 may be inserted into the first annular tube 1506and positioned near the first closed end 1508 of the first annular tube1506 and remote from the movable piston 1522. The barrier assembly 1530may at least partially define a boundary between the compression chamber1526 and the damping chamber 1528. In some embodiments, the barrierassembly 1530 may include a damping barrier 1532 and a damping seal1534. The barrier assembly 1530 may be designed to restrict or controlthe passage of compressed gas between the compression chamber 1526 andthe damping chamber 1528. In many embodiments, because the dampingbarrier 1532 may be configured to remain substantially stationary withinthe first annular tube 1506, the damping seal 1534 may be unnecessaryand the damping barrier 1532 may be designed to interfit with the firstannular tube 1506 with a tight tolerance. In other embodiments, it maybe desirable for the damping barrier 1532 to have a smaller diameterthan the diameter of the first annular tube 1506. The damping seal 1534may be configured to bridge the distance between the diameter of thedamping barrier 1532 and the diameter of the first annular tube 1506.Such a damping seal 1534 is conventional and may be selected by a personhaving ordinary skill in the art in a known manner based, at least inpart, on manufacturing tolerances, size, and the desired pressure of thepressurized gas within the first annular tube 1506. The compressionchamber 1526 may be on one side 1533 of the barrier assembly 1530 andthe damping chamber 1528 may be on another, opposite side 1535 of thebarrier assembly 1530.

The damper 1550 may include a first valve 1536 and a second valve 1538.The first valve 1536 may be positioned operatively between, and mayselectively permit compressed gas to flow from, the compression chamber1526 to the damping chamber 1528. The second valve 1538 may bepositioned operatively between, and may selectively permit compressedgas to flow from, the damping chamber 1528 to the compression chamber1526.

The first valve 1536 may include a first passageway 1540 that allows thepassage of gas between the compression chamber 1526 and the dampingchamber 1528. The first passageway 1540 may be serpentine. A firstblocker 1542 may be positioned adjacent to or within the firstpassageway 1540. In the embodiment shown in FIG. 15, the first blocker1542 may be a ball. A first bias, such as the spring 1544, may bepositioned adjacent the first blocker 1542. In many embodiments, thefirst bias 1544 may be a coil spring. In other embodiments, it may be aleaf spring or a resilient elastomer. Other biasing elements may also beused, if desired by a designer. In many embodiments, the first bias 1544may be configured to bias or urge the first blocker 1542 into a closedposition.

The first blocker 1542 may be acted upon by a variety of forces. First,the first blocker 1542 may be acted upon by gravity to move or retainthe first blocker 1542 in the closed position. Next, depending on theposition of the first bias 1544 and the adjuster 1546 (as will bedescribed in greater detail below), the first bias 1544 may also exert aforce on the first blocker 1542 urging it to its closed position. Inmany embodiments, the cumulative pressure or force of the compressed gasin the compression chamber 1526, damping chamber 1528, and in otherareas of the suspension unit may exert a force on the first blocker1542. These forces may combine to form an effective force applied to thefirst blocker 1542.

In use, a rider is likely to ride the vehicle over areas of terrain witha variety of obstacles. When a rider encounters an obstacle, thesuspension unit 1500 may be configured to absorb at least some of theforce of the impact. In such an instance, the movable piston assembly1512 may move upwardly within the first annular tube 1506. This movementmay serve to compress the compressible gas within the compressionchamber 1526. In some instances, the force of the compressible gas inthe compression chamber 1526 may function as in a conventionalsuspension. However, in other instances, the compression of thecompressible gas may actuate the damper 1550 to damp the compression andreduce shock passing to the rider.

When the piston assembly 1512 moves upward, it compresses thecompressible gas in the compression chamber 1526. This compressioncreates a pressure or force within the compression chamber 1526. Whenthe force in the compression chamber 1526 exceeds a threshold level offorce, this threshold level of force may overcome the effective force.This may move the first blocker 1542, thereby opening the first valve1536 and permitting the compressible gas to flow between the compressionchamber 1526 and the damping chamber 1528. In many embodiments, thecompressible gas may primarily flow from the compression chamber 1526through the serpentine passageway 1540 and into the damping chamber1528.

Pressure from the compressible gas in the compression chamber 1526 mayvariably open the first valve 1536. Because a portion of the effectiveforce urging the first blocker 1542 into a closed position may beapplied by a spring, such as the spring 1544, the effective force,particularly the effective spring force of the spring 1544 may vary,based on the degree to which the blocker 1542 is moved. This is due towell-known properties of springs. As the first blocker 1542 is moregreatly displaced, proportionally more force is required to move theblocker 1542 a greater distance. Accordingly, depending on the springconstant of the bias, varying amounts of force from the compressible gasin the compression chamber may cause varying degrees of opening of thefirst valve 1536. By selecting an appropriate bias 1544 and anappropriate size of the passageway 1540, a person having ordinary skillin the art may appropriately tune the first valve 1536 to open tovarying degrees at various thresholds of force. Such choices may improvea rider's feel, by damping the compression of the suspension unit,particularly upon the application of a sharp force to the suspensionunit. Such design choices are within the scope of a designer of ordinaryskill in the art.

Further, in some embodiments, the first valve 1536 may be configured toallow a user to adjust the damping properties of the damper 1550, andmore specifically, the first valve 1536. The damper 1550 may include anadjuster 1546 that may be manipulable by a user from the exterior of thevehicle. In some embodiments, the adjuster 1546 may be a knob. Theadjuster 1546 may be configured to directly or indirectly interact withthe first bias 1544 to reduce the force exerted by the first bias 1544by changing the preload on the bias 1544. The details of how theadjuster 1546 functions and the varying possible positions of theadjuster 1546 were analogously described in connection with otherembodiments. The features of the adjuster of the present embodiment aresubstantially similar and will not be further detailed for thisembodiment.

The damper 1550 may further include a second valve 1538. The secondvalve 1538 may include a second passageway 1548 that allows the passageof gas between the compression chamber 1526 and the damping chamber1528. The second passageway 1548 may be one or a plurality of aperturesdefined within the damping barrier 1532. A second blocker 1552 may bepositioned adjacent the second passageway 1548 and may be configured toselectively open and close to restrict or control the flow of compressedgas from the damping chamber 1528 to the compression chamber 1526. Inthe embodiment of FIG. 15, the second blocker 1552 may be a tapered pincapable of interfitting with the second passageway 1548. A second bias,such as the spring 1554, may be positioned adjacent the second blocker1552 to define the properties under which the second blocker 1552 maymove to its open position. In many embodiments, the second bias 1554 maybe a coil spring. In other embodiments, it may be a leaf spring or aresilient elastomer. Other biasing elements may also be used, if desiredby a designer. In many embodiments, the second bias is configured tobias or urge the second blocker 1552 into a closed position.

The embodiment of FIGS. 16 and 17 share many elements in common with theembodiment of FIG. 15. The function of the embodiments is substantiallythe same. Many of the structural elements are substantially the same asthose in FIG. 15. Only where there is a difference is the differencedescribed. In addition, most of the design changes between theconfigurations can be mixed and matched. A person having ordinary skillin the art will be able to make such changes without undueexperimentation.

Turning now to the embodiment of FIGS. 16 and 17, it is noted that thedamping chamber is positioned annularly around the compression chamber,rather than being inline with the compression chamber as with otherembodiments. In many embodiments incorporated into a rear shock, it maybe desirable to use such a configuration, rather than attempting to makean inline system. The use of an annular damping chamber may allow for agreater distance of travel for the piston, thereby creating an improvedride feel in many embodiments. A person having ordinary skill in the artis able to modify any of the described embodiments to position anappropriate valve or valves drawn from any of the other embodiments inthe manner shown in FIGS. 16 and 17 and described herein to make such anadjustment. While this positioning of the damping chamber is shown onlyin connection with a rear shock, it is possible to modify a front forkto use a similar damping chamber. Further, if desired, the dampingchamber could be positioned remote from the compression chamber in anyembodiment and connected with a tube or another device allowing the flowof compressed gas. Such devices should be considered as falling withinthe scope of the disclosure and claims.

In the embodiment of FIGS. 16 and 17, a damper 1650 may be incorporatednear the closed end 1608 of the first annular tube 1606. The firstannular tube 1606 may define a compression chamber 1602 and an annulardamping chamber 1604. In some embodiments, the damping chamber 1604 maybe concentric with the compression chamber 1602. The piston 1622 mayslidingly interfit with an inner diameter 1607 of the first annular tube1606 and may be capable of compressing a compressible gas in thecompression chamber 1602.

The damper 1650 may be incorporated into the first annular tube 1606. Abarrier assembly 1630 may be positioned at the closed end 1608 of thefirst annular tube 1606 and remote from the movable piston 1622. Thebarrier assembly 1630 may define a boundary between the compressionchamber 1602 and the damping chamber 1604. The barrier assembly 1630 maybe designed to restrict or control the passage of compressed gas betweenthe compression chamber 1602 and the damping chamber 1604. Thecompression chamber 1602 may be on one side of the barrier assembly 1630and the damping chamber 1604 may be on another side of the barrierassembly 1630.

The damper 1650 may include a first valve 1636 and a second valve 1638.The first valve 1636 may be positioned operatively between and mayselectively permit compressed gas to flow from the compression chamber1602 to the damping chamber 1604. The second valve 1638 may bepositioned operatively between and may selectively permit compressed gasto flow from the damping chamber 1604 to the compression chamber 1602.

The first valve 1636 may include a first passageway 1640 that allows thepassage of gas between the compression chamber 1602 and the dampingchamber 1604. The first passageway 1640 may be serpentine. A firstblocker 1642 may be positioned adjacent to or within the firstpassageway 1640. In the embodiment shown in FIGS. 16 and 17, the firstblocker 1642 may be a ball. A first bias, such as the spring 1644, maybe positioned adjacent the first blocker 1642. In many embodiments, thefirst bias 1644 may be a coil spring. In other embodiments, it may be aleaf spring or a resilient elastomer. Other biasing elements may also beused, if desired by a designer. In many embodiments, the first bias 1644may be configured to bias or urge the first blocker 1642 into a closedposition.

The first blocker 1642 may be acted upon by a variety of forces. First,the first blocker 1642 may be acted upon by gravity to move or retainthe first blocker 1642 in the closed position. Next, depending on theposition of the first bias 1644 and the adjuster 1646 (as will bedescribed in greater detail below), the first bias 1644 may also exert aforce on the first blocker 1642 urging it to its closed position. Inmany embodiments, the cumulative pressure or force of the compressed gasin the compression chamber 1602, damping chamber 1604, and in otherareas of the suspension unit may exert a force on the first blocker1642. These forces may combine to form an effective force applied to thefirst blocker 1642.

In use, a rider is likely to ride the vehicle over areas of terrain witha variety of obstacles. When a rider encounters an obstacle, thesuspension unit 1600 may be configured to absorb at least some of theforce of the impact. In such an instance, the movable piston assembly1612 may move upwardly within the first annular tube 1606. This movementmay serve to compress the compressible gas within the compressionchamber 1602. In some instances, the force of the compressible gas inthe compression chamber 1602 may function as in a conventionalsuspension. However, in other instances, the compression of thecompressible gas may actuate the damper 1650 to damp the compression andreduce shock passing to the rider.

When the piston assembly 1612 moves upward (to the left in theorientation of FIG. 16), it compresses the compressible gas in thecompression chamber 1602. This compression creates a pressure or forcewithin the compression chamber 1602. When the force in the compressionchamber 1602 exceeds a threshold level of force, this threshold level offorce may overcome the effective force. This may move the first blocker1642, thereby opening the first valve 1636 and permitting thecompressible gas to flow between the compression chamber 1602 and thedamping chamber 1604. In many embodiments, the compressible gas mayprimarily flow from the compression chamber 1602 through the serpentinepassageway 1640 and into the damping chamber 1604.

Pressure from the compressible gas in the compression chamber 1602 mayvariably open the first valve 1636. Because a portion of the effectiveforce urging the first blocker 1642 into a closed position may beapplied by a spring, such as the spring 1644, the effective force,particularly the effective spring force of the spring 1644 may vary,based on the degree to which the blocker 1642 is moved. This is due towell-known properties of springs. As the first blocker 1642 is moregreatly displaced, proportionally more force is required to move theblocker 1642 a greater distance. Accordingly, depending on the springconstant of the bias, varying amounts of force from the compressible gasin the compression chamber may cause varying degrees of opening of thefirst valve 1636. By selecting an appropriate bias 1644 and anappropriate size of the passageway 1640, a person having ordinary skillin the art may appropriately tune the first valve 1636 to open tovarying degrees at various thresholds of force. Such choices may improvea rider's feel, by damping the compression of the suspension unit,particularly upon the application of a sharp force to the suspensionunit. Such design choices are within the scope of a designer of ordinaryskill in the art.

Further, in some embodiments, the first valve 1636 may be configured toallow a user to adjust the damping properties of the damper 1650, andmore specifically, the first valve 1636. The damper 1650 may include anadjuster 1646 that may be manipulable by a user from the exterior of thevehicle. In some embodiments, the adjuster 1646 may be a knob. Theadjuster 1646 may be configured to directly or indirectly interact withthe first bias 1644 to reduce the force exerted by the first bias 1644by changing the preload on the bias 1644. The details of how theadjuster 1646 functions and the varying possible positions of theadjuster 1646 were analogously described in connection with otherembodiments. The features of the adjuster of the present embodiment aresubstantially similar and will not be further detailed for thisembodiment.

The damper 1650 may further include a second valve 1638. The secondvalve 1638 may include a second passageway 1648 that allows the passageof gas between the compression chamber 1602 and the damping chamber1604. The second passageway 1648 may be one or a plurality of aperturesdefined within the barrier assembly 1630. A second blocker 1652 may bepositioned adjacent the second passageway 1648 and may be configured toselectively open and close to restrict or control the flow of compressedgas from the damping chamber 1604 to the compression chamber 1602. Asecond bias, such as the spring 1654, may be positioned adjacent thesecond blocker 1652 to define the properties under which the secondblocker 1652 may move to its open position. In many embodiments, thesecond bias 1654 may be a coil spring. In other embodiments, it may be aleaf spring or a resilient elastomer. Other biasing elements may also beused, if desired by a designer. In many embodiments, the second bias isconfigured to bias or urge the second blocker 1652 into a closedposition.

This detailed description in connection with the drawings is intendedprincipally as a description of the presently preferred embodiments ofthe invention, and is not intended to represent the only form in whichthe present invention may be constructed or utilized. The descriptionsets forth the designs, functions, means, and methods of implementingthe invention in connection with the illustrated embodiments. It is tobe understood, however, that the same or equivalent functions andfeatures may be accomplished by different embodiments that are alsointended to be encompassed within the spirit and scope of the inventionand that various modifications may be adopted without departing from theinvention or scope of the following claims.

The invention claimed is:
 1. A suspension unit for a bicycle,comprising: an annular tube defining a compression chamber; a pistonslidingly interfitting with the annular tube and capable ofreciprocating with respect to the annular tube, the piston capable ofcompressing a compressible gas in the compression chamber; a barrierassembly remote from the piston, comprising a damping barrier in fixedposition near one end of the annular tube, the compression chamber beingon one side of the barrier assembly and a damping chamber being onanother side of the barrier assembly; and a first valve adjacent thedamping barrier and operatively between the compression chamber and thedamping chamber and capable of permitting the compressible gas to flowbetween the compression chamber and the damping chamber; wherein aneffective force is applied to a blocker in the first valve, theeffective force influencing a threshold level of force of compressed gasin the compression chamber capable of opening the first valve.
 2. Thesuspension unit for a bicycle according to claim 1, wherein theeffective force is at least partially applied by a bias.
 3. Thesuspension unit for a bicycle according to claim 2, wherein the bias isa spring.
 4. The suspension unit for a bicycle according to claim 1,wherein the blocker comprises a resilient material, the resilientmaterial applying at least part of the effective force.
 5. Thesuspension unit for a bicycle according to claim 1, wherein the barrierassembly is connected to the annular tube in a substantially fixedposition.
 6. The suspension unit for a bicycle according to claim 1,wherein the barrier assembly is adjustably connected to the annulartube.
 7. The suspension unit for a bicycle according to claim 1, whereinthe barrier assembly is located substantially within the annular tube.8. The suspension unit for a bicycle according to claim 1, furthercomprising an adjuster operatively connected to the first valve andcapable of adjusting at least a portion of the effective force.
 9. Thesuspension unit for a bicycle according to claim 1, wherein the barrierassembly and a shaft connecting the barrier assembly to the annular tubeat least partially define a serpentine passageway.
 10. The suspensionunit for a bicycle according to claim 1, further comprising a secondvalve operatively between the compression chamber and the dampingchamber and capable of permitting the compressible gas to flow betweenthe damping chamber and the compression chamber.
 11. A suspension unitfor a bicycle, comprising: an annular tube defining a compressionchamber and a damping chamber, each of the compression chamber and thedamping chamber being filled with a compressible gas; a movable pistonslidingly fitting within the annular tube; a damping barrier in fixedposition near one end of the annular tube and remote from the movablepiston, the compression chamber being on one side of the damping barrierand a damping chamber being on another side of the damping barrier; anda first valve adjacent the damping barrier and operatively between thecompression chamber and the damping chamber and permitting thecompressible gas to flow between the compression chamber and the dampingchamber, the first valve comprising a first bias, the first bias atleast partially contributing to an effective force applied to a blocker,the effective force capable of being overcome by a threshold level offorce of compressed gas in the compression chamber.
 12. The suspensionunit for a bicycle according to claim 11, further comprising a secondvalve operatively between the compression chamber and the dampingchamber and permitting the compressible gas to flow between the dampingchamber and the compression chamber, the second valve comprising asecond bias capable of being overcome by a threshold level of force ofcompressed gas in the damping chamber.
 13. The suspension unit for abicycle according to claim 12, wherein the second valve furthercomprises a shim.
 14. The suspension unit for a bicycle according toclaim 13, wherein the second bias comprises a second spring urging theshim into a closed position.
 15. The suspension unit for a bicycleaccording to claim 11, wherein the first bias comprises a first blockerformed at least in part from a resilient material.
 16. The suspensionunit for a bicycle according to claim 15, further comprising an adjusteroperatively connected to the first blocker capable of adjusting aneffective spring force of the resilient material.
 17. The suspensionunit for a bicycle according to claim 12, wherein the second valve ispositioned adjacent at least one of the damping barrier and the shaft.18. The suspension unit for a bicycle according to claim 11, wherein thedamping barrier is connected to the first annular tube in asubstantially fixed position.
 19. The suspension unit for a bicycleaccording to claim 18, wherein the damping barrier is connected to thefirst annular tube using a shaft that is annular along at least aportion of its length.
 20. The suspension unit for a bicycle accordingto claim 19, wherein the first valve is positioned adjacent at least oneof the damping barrier and the shaft.
 21. The suspension unit for abicycle according to claim 19, wherein the damping barrier and the shaftat least partially define a serpentine passageway.
 22. The suspensionunit for a bicycle according to claim 11, wherein the first valvefurther comprises a first blocker and the first bias comprises a firstspring positioned adjacent the first blocker.
 23. The suspension unitfor a bicycle according to claim 22, further comprising an adjusteroperatively connected to the first spring capable of adjusting aneffective spring force of the first spring.
 24. The suspension unit fora vehicle according to claim 22, wherein the first blocker comprises apin.
 25. The suspension unit for a vehicle according to claim 22,wherein the first blocker comprises a ball.
 26. The suspension unit fora bicycle according to claim 11, wherein the barrier assembly is locatedsubstantially within the annular tube.
 27. A suspension unit for abicycle, comprising: an annular tube defining a compression chamber; apiston slidingly interfitting with the annular tube and capable ofreciprocating with respect to the annular tube, the piston capable ofcompressing a compressible gas in the compression chamber; a barrierassembly remote from the piston and near one end of the annular tube,the compression chamber being on one side of the barrier assembly and adamping chamber being on another side of the barrier assembly; a firstvalve operatively between the compression chamber and the dampingchamber and capable of permitting the compressible gas to flow betweenthe compression chamber and the damping chamber; and an adjusteroperatively connected to the first valve and having at least threepositions, wherein the adjuster is capable of adjusting an effectiveforce capable of being overcome by a threshold level of force ofcompressed gas in the compression chamber, wherein a maximum effectiveforce exists when the adjuster is in contact with a portion of the firstvalve.
 28. The suspension unit for a bicycle according to claim 27,wherein the first valve includes a bias.
 29. The suspension unit for abicycle according to claim 28, wherein the adjuster is capable ofadjusting an effective spring force of the bias.
 30. The suspension unitfor a bicycle according to claim 28, wherein the bias is a spring andthe adjuster is capable of adjusting an effective spring force of thespring.
 31. The suspension unit for a bicycle according to claim 28,wherein the bias is a resilient material from which at least a portionof the first valve is formed and the adjuster is capable of adjusting aneffective spring force of the resilient material.
 32. The suspensionunit for a bicycle according to claim 28, wherein the first bias isadjustable by the adjuster between a first position relativelysubstantially allowing the flow of compressed gas from the compressionchamber to the damping chamber, a second position relativelysubstantially restricting the flow of compressed gas from thecompression chamber to the damping chamber, and at least a thirdposition between the first position and the second position, relativelypartially restricting the flow of compressed gas from the compressionchamber to the damping chamber.
 33. The suspension unit for a bicycleaccording to claim 32, wherein at least a portion of the first valve isadjustable by the adjuster between a first position relativelysubstantially allowing the flow of compressed gas from the compressionchamber to the damping chamber, a second position relativelysubstantially restricting the flow of compressed gas from thecompression chamber to the damping chamber, and at least a thirdposition between the first position and the second position, relativelypartially restricting the flow of compressed gas from the compressionchamber to the damping chamber.
 34. The suspension unit for a bicycleaccording to claim 27, further comprising a second valve operativelybetween the compression chamber and the damping chamber and capable ofpermitting the compressible gas to flow between the damping chamber andthe compression chamber.
 35. The suspension unit for a bicycle accordingto claim 27, wherein the adjuster is substantially infinitely adjustablebetween a first extreme position and a second extreme position.
 36. Thesuspension unit for a bicycle according to claim 27, wherein the firstvalve comprises a blocker adjustable by the adjuster between a firstposition relatively substantially allowing the flow of compressed gasfrom the compression chamber to the damping chamber, a second positionrelatively substantially restricting the flow of compressed gas from thecompression chamber to the damping chamber, and at least a thirdposition between the first position and the second position, relativelypartially restricting the flow of compressed gas from the compressionchamber to the damping chamber.
 37. A suspension unit for a bicycle,comprising: an annular tube defining a compression chamber; a pistonslidingly interfitting with the annular tube and capable ofreciprocating with respect to the annular tube, the piston capable ofcompressing a compressible gas in the compression chamber; a barrierassembly remote from the piston and near one end of the annular tube andfixed with respect to the annular tube, comprising a damping barriernear one end of the annular tube, the compression chamber being on oneside of the barrier assembly and a damping chamber having asubstantially fixed volume and being on another side of the barrierassembly; a first valve adjacent the barrier assembly and operativelybetween the compression chamber and the damping chamber and capable ofpermitting the compressible gas to flow between the compression chamberand the damping chamber; and a first passageway defined between thedamping chamber and the compression chamber; wherein pressure from thecompressible gas in the compression chamber is capable of variablyopening the first valve, thereby changing an effective size of the firstpassageway.
 38. The suspension unit for a bicycle according to claim 37,further comprising a second valve operatively between the compressionchamber and the damping chamber and capable of permitting thecompressible gas to flow between the damping chamber and the compressionchamber.
 39. The suspension unit for a bicycle according to claim 37,wherein the first valve further comprises a first bias.
 40. Thesuspension unit for a bicycle according to claim 39, the first valvefurther comprising a first blocker, and wherein an effective springforce applied by the first bias to the first blocker at least partiallydefines a threshold level of force in the compression chamber capable ofopening the first valve.
 41. The suspension unit for a bicycle accordingto claim 39, wherein the first bias is a spring.
 42. The suspension unitfor a bicycle according to claim 37, wherein the first valve comprises afirst blocker comprising a resilient material, and wherein an effectivespring force applied by the first blocker at least partially defines athreshold level of force in the compression chamber capable of openingthe first valve.
 43. The suspension unit for a bicycle according toclaim 37, further comprising an adjuster operatively connected to thefirst valve and capable of adjusting the variability of opening of thefirst passageway.
 44. The suspension unit for a bicycle according toclaim 37, wherein the first passageway is serpentine.
 45. The suspensionunit for a bicycle according to claim 37, wherein the barrier assemblyis located substantially within the annular tube.